Large Scale Network Address Translation
The NetScaler ADC now supports NAT44 Large Scale NAT
(LSN) and is compliant with RFC 6888, 5382, 5508, and 4787.
The phenomenal growth of the internat has resulted in
the shortage of public IPv4 addresses. CGN provides a solution to this
issue by maximizing the use of available public IPv4 addresses by
sharing few public IPv4 addresses among a large pool of Internet users.
CGN is a collection of technologies and NAT44 is one of them.
NAT44 LSN translates private IPv4 address in public IPv4
addresses. It includes network address and port translation methods to
aggregate many private IP addresses into fewer public IPv4 addresses.
NAT44 LSN is designed to handle NAT in large scale.
The LSN feature of the NetScaler ADC is very useful for
Internet Service Providers (ISPs), carriers, and in enterprise data
centers, providing millions of translations to support a large number
of users, and at very high bandwidth throughput.
Note: Large Scale NAT is also called Carrier Grade NAT.
The following are some of the sub-features of LSN on a
* Mapping: Support of Endpoint-independent mapping
(EIM), Address-dependent mapping ( ADM), and Address-Port dependent
* Filtering: Support of Endpoint-independent filtering
(EIF), Address-dependent filtering, and Address-Port-dependent
* Quotas: Configurable limits on number of ports and
sessions per subscriber.
* Static Mapping: Support of manually defining an LSN
* Hairpin Flow: Support for communication between
subscribers or internal hosts using public IP addresses.
* ALGs: Support of application Layer Gateway (ALG) for
FTP, ICMP, and TFTP protocols.
* LSN Clients: Support for specifying or identifying
subscribers for LSN NAT by using IPv4 addresses and extended ACL rules.
* Deterministic/ Fixed NAT: Support for pre-allocation
of block of ports to subscribers for minimizing logging.
* Logging: Support for logging LSN session for law